A rolled steel wire is normally formed immediately after rolling into a horizontally oriented and advancing helix having a plurality of vertically standing turns. This helix or coil is fed into the upstream end of a horizontally extending tube that is rotated about its central horizontal axis. Water is sprayed tangentially into this upstream end and air jets are directed tangentially into the downstream end of the cooling tube. In this manner a water film is formed on the interior of the tube, so that the coil is cooled by this water as it advances horizontally along the tube.
This known method has several disadvantages. First of all conveying the wire with its turns oriented vertically presents some difficulty, and frequently results in the coil collapsing and jamming the apparatus. Furthermore, the cooling effect is bad to control, and it is quite difficult to form a perfectly uniform layer of water on the inside of the tube, as is necessary for most effective cooling. Normally the layer of water is much deeper at the bottom of the tube than at the top, so that the turns of the coil or helix will not be uniformally treated.